1. Field of the Invention
The present invention relates to an insertion apparatus, for example an endoscope, including an insertion section configured to be inserted into a body cavity or a pipe. More particularly, the present invention relates to an insertion apparatus including a fixing mechanism configured to prevent an intended motion state of a motion portion in an insertion section from being readily released by an external force that acts on the motion portion when maintaining the motion portion in the insertion section in the intended motion state.
2. Description of the Related Art
As an insertion apparatus including an insertion section configured to be inserted into a body cavity, a pipe, or the like, there is, e.g., an endoscope. The endoscope is used for observation and the like of a body tissue in a body cavity in the medical field, or for observation and the like of an inner wall of a pipe in the industrial field. Such an endoscope includes a holding section (a grip) provided to a proximal direction side of an insertion section. In the holding section are provided with a knob configured to perform a bending operation of a bending section, and various operation input portions such as an air supply/water supply switch of the bending section.
As such operation input portions, there are a lever configured to perform an operation of fixing and holding a bent state of the bending section at a desired position and a hardness adjustment knob configured to change a hardness of a flexible tube section provided on a part to the proximal direction side of the bending section in the insertion section as disclosed in Jpn. Pat. Appln. KOKAI Publication No. Hei 9-294710, and others. In the endoscope according to Jpn. Pat. Appln. KOKAI Publication No. Hei 9-294710, a hardness adjustment knob is provided on a holding section. Further, in the insertion section, a hardness adjustment wire is extended along a longitudinal axis. A distal end of the hardness adjustment wire is fixed between a bending section and a flexible tube section. A proximal end of the hardness adjustment wire is wound around a pulley provided in the holding section. Furthermore, the hardness adjustment wire is inserted through a coil pipe extended in the insertion section along the longitudinal axis. A distal end of the coil pipe is fixed to a distal end portion of the hardness adjustment wire. A proximal end of the coil pipe is fixed to an inner peripheral portion of the holding section.
At the time of hardening the flexible tube section, the pulley is rotated by hardness adjustment using the hardness adjustment knob. As a result, the hardness adjustment wire is pulled. When the hardness adjustment wire is pulled, the coil pipe shrinks (contracts) in directions parallel to the longitudinal axis. When the coil pipe shrinks, the flexible tube section is hardened.